During an inspection, what should the operator check if there is no refrigerant inside the evaporator?

In refrigeration systems, if there is no refrigerant inside the evaporator, it indicates a potential issue in the refrigerant flow. The metering device is crucial in regulating the flow of refrigerant from the condenser to the evaporator. If the metering device is malfunctioning or blocked, it can prevent refrigerant from entering the evaporator, leading to a lack of refrigerant in that component.

By checking the metering device, an operator can ensure it is functioning correctly, allowing proper refrigerant flow. A faulty metering device may show signs like restricted flow or an improper opening, which would explain the absence of refrigerant in the evaporator.

Other components, such as the compressor and condenser, while important to the overall system operation, would not directly explain the lack of refrigerant in the evaporator without first addressing the metering device. Consequently, checking the metering device is the most logical first step in diagnosing the issue.